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LAUNCHCC3235MOD: RF section with an external antenna

Part Number: LAUNCHCC3235MOD

Hi,

I am planning on designing a custom board for the CC3235MODSF12MOBR and use an external antenna. The reference design shows C38, C35, C36, C37, R48 passive components. Are all of them required for an external antenna?

  • Hi,

    This components are for matching RF output to 50 ohm impedance. Components values depends on your RF design and manufacturing of your PCB. At first step you should calculate this matching components according your RF design after that validate your prototypes at VNA.

    This is a nice video about RF design optimisation.

    Jan

  • Hi Jan,

    Thank you for your reply. My board layer stack, layout, and traces are identical to those from the development kit. If I install all the parts shown on the reference schematic will I get the 50 Ohm impedance required?

  • Hi,

    Probably yes, but RF path impedance depends on manufacturing of PCB as well and from this reason there can be impedance mismatch. But it is likely that this will not be big issue.

    Do measurements by the VNA will be still best way to ensure that design is correct.

    Jan